21642137164 has 24 divisors (see below), whose sum is σ = 41079700368. Its totient is φ = 9936130560.

The previous prime is 21642137107. The next prime is 21642137171. The reversal of 21642137164 is 46173124612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3878514 + ... + 3884089.

It is an arithmetic number, because the mean of its divisors is an integer number (1711654182).

Almost surely, 2^21642137164 is an apocalyptic number.

It is an amenable number.

21642137164 is a deficient number, since it is larger than the sum of its proper divisors (19437563204).

21642137164 is a wasteful number, since it uses less digits than its factorization.

21642137164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7762665 (or 7762663 counting only the distinct ones).

The product of its digits is 48384, while the sum is 37.

The spelling of 21642137164 in words is "twenty-one billion, six hundred forty-two million, one hundred thirty-seven thousand, one hundred sixty-four".